LED Control
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 59
Buffer Manager
The buffer manager maintains pools of internal memory used in transmit and receive functions. The buffer
manager has logic blocks for allocation, free, control, and initialization of internal memory pools. The receive
MAC requests NIC Rx Mbuf memory so inbound frames can be buffered. The read DMA engine requests the
device Tx Mbuf memory for buffering the packets from host memory before they are sent out on the wire. The
DMA write engine requests a small amount of internal memory for DMA and interrupt operations. The usage of
this internal memory is transparent to host software, and does not affect device/system performance.
LED Control
Refer to section “LED Control” in the applicable data sheet.
Memory Arbiter
The Memory Arbiter (MA) is a gatekeeper for internal memory access. The MA is responsible for decoding the
internal memory addresses that correspond to Ethernet controller data structures and control maps. If a
functional block faults or traps during access to internal memory, the MA handles the failing condition and reports
the error in a status register. In addition to architectural blocks, the MA provides a gateway for the RISC
processor to access local memory. The RISC has an MA interface that pipelines up to three access requests.
The MA negotiates local memory access, so all portions of the architecture are provided with fair access to
memory resources. The MA prevents starvation and bounds access latency. Host software may enable/disable/
reset the MA, and there are no tunable parameters.